I like using la's totally awesome orange to get off dirt, etc. Remarkable stuff found at the dollar store
magic eraser if something just won't gtfo (small marks)
Star brite mildew remover for mildew etc
Star brite vinyl polish and cleaner to whiten it up (love this stuff)
303 to finish it all off

be careful with the magic eraser. It is abrasive and if you use it enough it will dull.tear apart your seats.